1. Field of the Invention
The present invention relates generally to dishwashers and more particularly to a non-electric, self-contained, dishwasher unit adapted to be removably interconnected with either a high pressure, medium pressure or low pressure domestic water supply.
2. Discussion of the Prior Art
Portable dishwashers operable soley by water pressure are not new. Several such units have been manufactured and sold in recent years. A common drawback of such units, however, has been their inability to rapidily and effectively clean dishes and cookware and their inability to operate satisfactorily when connected to domestic water supplies.
Many of the prior art units are cheaply constructed and have been sold more as novelty item than as a bona fide, high perfomance dishwashing device. Generally, the washing action in such units is attempted by one or more rapidly rotating emitters located beneath or along side a rack holding the dishes. These emitters, which operate in much the same manner as lawn sprinklers, have proven ineffective in the removal of most troublesome types of food residue on the dishes. Other types of emitters have from time to time been tried, but for the most part have also proven to be ineffective.
Included among the most effective dishwasher units ever developed are the units discussed in U.S. Pat. Nos. 4,368,747 and 4,444,213 owned by the assignee of the present application. These units, for the first time, overcome the quality and performance drawbacks inherent in their predecessor prior art devices. Like the apparatus of these earlier designs, the present invention is not a toy, or a novelty item, but rather is a carefully engineered, high performance device adapted to rapidly and efficiently remove even the most difficult food residue from dishes and cookware. The improved water jet means of the unit of the present invention controllably directs a multiplicity of high velocity water jets at the articles to be washed while they are supported within the unit on a unique holding rack which is precisely rotated at an optimum rate of speed without regard to the pressure of the domestic water supply. These water jets can be directed to impinge upon all the surfaces of the dishes supported within the rotating rack and create a unique scrubbing type of action which loosens and dislodges even the most difficult of residues. A dosing chamber of improved design precisely mixes an emulsifier, such as siquid soap, with the water upstream of the water jets thereby enhancing the cleaning efficiency of the device.
An important aspect of the present invention is the improved water jet means which enables the unit to work at peak efficiency even when attached to domestic water systems having very low pressures of on the order of 5 to 10 psi. The water jet means comprises an adjustable first collimated jet means which can be used in low water pressure situations to initiate and assist in sustaining the rotation of the rotatable rack which supports the dirty dishes. The water jet means also includes an adjustable second spray jet means which accomplishes the efficient scrubbing and cleansing action and also functions to sustain the rotation of the rack. The control means which are operably associated with the jet means permit the collimated jet means to be used at full pressure in low water pressure conditions, to be discontinued under normal water pressure conditions or to be used in high water pressure conditions to effect a braking action to the rotating rack. Accordingly, the unique control means of the invention permits the rack to always be rotated at an optimum rate of speed for maximum cleaning efficiency by the spray jet means regardless of the water pressure of the domestic water source to which the apparatus is connected.
The spray jet means of the device is readily adjustable with respect to the rack so that a multiplicity of fine, very high velocity water jets bombard the dishes from all angles, from above, from below and from the sides. The unique hole pattern formed in the spray jet means permits optimum controlled rotation of the supporting rack while at the same time accomplishing maximum cleaning and scrubbing of the dishes.
Another important aspect of the present invention resides in the provision of a novel timer valve apparatus embodied in the diswasher unit for automatically and adjustably controlling the period of time during which the domestic water will flow into the unit.